Rapid Engineering UHAT 150, Installation, Operation & Service Manual

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UHA S
TANDARD
U
NIT
H
EATER
I
NSTALLATION
O
PERATION AND
S
ERVICE
M
ANUAL
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14.3 Troubleshooting for Flame Supervision System
NOTE: Minimum flame probe current 1 µA DC. Typical flame probe current 3-5 µA DC.
Repair or replace as
required.
If problems persist, contact
Rapid Engineering LLC at
www.rapidengineering.com
Replace ignition control.
Use General
Troubleshooting section to
trace the fault.
Heater Operating
TROUBLESHOOT ENDS.
No
Repair or replace as
required.
Is inlet burner gas pressure
correct? Is live and neutral
polarity correct? Is
flame probe circuit correct?
Is there a current flowing in
the flame probe circuit with
no flame present?
Yes
No
Does “lockout” occur when
there is a flame present?
Yes
Is the connecting lead
damaged? Is the flame probe
damaged or touching earthed
components?
No
Is the flame present and
at least 1 µA DC flame
current?
Connect a DC ammeter in
series with the flame probe.
Yes
No
Yes
Yes
No
START
To measure flame current, connect a 0 - 50 µA DC meter in series with the flame probe. If the meter
reads negative values, then reverse the test leads.